Surface mounted printed circuit board connectors, particularly elongated connectors such as edge-card connectors or SIMM sockets, typically use mounting pegs or boardlocks to locate the connectors on a printed circuit board and to hold the surface mount leads of the connectors to the printed circuit board during soldering of the leads to the board circuit traces. If the connector is not properly held to the circuit board during soldering, the leads can move off of the surface of the board or become misaligned with the circuit traces or solder pads entirely. This would result in open circuit conditions and a defective connection between the connector and the board.
On the other hand, if the retention of the connector to the circuit board is not sufficiently compliant, particularly in elongated connectors, thermal expansion of the connector housing relative to the circuit board during soldering can cause bowing of the connector between two rigidly held areas, again resulting in the surface mount leads not making contact with the circuit traces or solder pads on the board.
Still further, surface mount connector applications often use double-sided circuit boards on which components, including the connectors, are mounted on each side of the board. This requires subjecting each side of the board to a solder reflow process, resulting in the connectors on the underside of the board traveling upside down during heating of the upper surface. The mounting pegs therefore must hold the connector to the board in such conditions so that the leads remain in contact with the circuit board traces. Furthermore, the mounting pegs cannot protrude through the board to the opposite side of the board where they may interfere with other components. Consequently, mounting pegs having protruding boardlocks or hook portions simply cannot be used.
There is a need for an improved mounting peg system for surface mounted printed circuit board connectors having sufficient retention force to hold the connectors on the circuit board during soldering, yet providing sufficient compliance to accommodate thermal expansion of the connectors relative to the circuit board, while maintaining the mounting pegs within the plane of the printed circuit board. This invention is directed to satisfying this need and solving the problems outlined above.